阳离子交换树脂催化制备三辛酸甘油酯工艺研究

OPTIMIZATION OF THE PREPARATION PROCESS OF TRICAPRILIN CATALYZED BY CATION EXCHANGE RESIN

以辛酸和甘油为原料,阳离子交换树脂HND-6为催化剂,采用直接酯化法制备三辛酸甘油酯。建立了三辛酸甘油酯的高效液相色谱标准曲线,回归方程为y=974 980x+1 197(R2=0.999 0)。以三辛酸甘油酯的转化率为评价指标,研究三辛酸甘油酯酯化合成的工艺,通过单因素试验考察了反应时间、反应温度、辛酸甘油物质的量之比和催化剂添加量4个因素对三辛酸甘油酯转化率的影响,在单因素试验的基础上,采用Box-Benhnken试验设计原理对工艺条件进行响应面优化。结果表明:最优工艺条件为反应时间7 h,反应温度113℃,辛酸甘油物质的量之比5.3∶1,催化剂添加量65%(甘油质量计,相当于反应物总质量的6.99%),在此条件下三辛酸甘油酯转化率为87.52%,与理论预测值基本一致。

Tricaprylin was prepared by direct esterification method with caprylic acid and glycerol as raw material and cation exchange resin HND-6 as catalyst.The standard curve of tricaprylin used for the qualitative and quantitative analysis was established by high performance liquid chromatography and the regression equation was y=974 980x+1 197(R2=0.999 0).The effect of reaction time,reaction temperature,molar ratio of caprylic acid to glycerol and catalyst loading addition amount on the conversion rate of tricaprylin was investigated by single factor test.Response Surface Methodology(RSM)adopting Box-Benhnken Design(BBD)principle was used to further optimize the preparation processing conditions on the bases of single factor test.The results showed that the optimal conditions were as follows:reaction time 7 h,reaction temperature 113℃,substrates molar ratio 5.3∶1,catalyst addition amount 65%(based on mass of glycerol,equivalent to 6.99%of the total substrates mass).Under the above conditions,the conversion rate of tricaprylin reached to 87.52%,which was nearly consistent with the predicted value.